Primer Piercing?

[Pyscodog]

Recently purchased a 722 Rem. in 17 caliber. A friend gave me some of his reloads to try out and after about 6 rounds, it pierced a primer. I bought a box of factory Rem. ammo today and shot about 10 rounds and it pierced another. I shot 5 more with no problems. My friend said my firing pin is to long. If its to long, wouldn't it pierce all of them? Kinda stumped on this one. Any ideas?
pyscodog

 

[Kenny474]

Several issues can cause primer piercing, one of them being excessive firing pin protrusion. Another area to look into is excessive space around the firing pin, ie: too large of a firing pin hole. Many shooters go to a smaller diameter pin and bush the hole in the bolt for closer tolerance around the pin. That will allow higher pressure before you see piercing in most cases. I believe some also use a bit lighter firing pin spring as well, but I have never done this myself and someone else will know more on that than I.

Another issue is using reloads not tailored to your rifle. Your rifle is not your friends, and may very well handle pressure differently. Honestly, you are lucky all you ended up with was a pierced primer, as much worse can and has happened. Good rule to go by, if they are more than 10% over start load, don't use them unless you have worked up to that point in your specific rifle. I understand you also had the same issue in factory loads, so it is probably more of an issue with your rifle, but it's still best to only use reloads that you have developed for your rifle.

Unless you have experience with working on your own rifles, you may be better off and save yourself a headache by just having a smith take a look at it and adjust what needs to be fixed. You can also have the firing pin hole bushed at the same time, and that will give benefit as well in regards to handling more pressure before you experience primer piercing.

If you do your own rifle work, investigate the areas I listed above. They will likely solve your issue, and I'm sure others will point out areas I missed as well.

Good luck
Kenny

 

[Preacher]

The number 1 rule is to NOT use other folks reloads...... period... unless they were set up for your rifle...
The 17 is a hot round and you really need the firing pin hole bushed if your having problems.
Send it to Gre-Tan and you'll have it back in a weeks time...

 

[Pyscodog]

Any ideas of the cost to bush the firing pin?

Also, the reloads belonged to a friend and I trust his loads. Anyone else's, I wouldn't even consider.
Thanks for the info!

 

[bheadboy]

i may be wrong, but i can not find where Rem built a factory 722 in 17cal

if this is true, the chamber, bbl are then custom and could be very different from a factory version. the fireing pin diamier and hole would have been designed for the 222 case, but in early production may well be different from later versions or a custome set up..

Bob

 

[Pyscodog]

Your correct, Rem. didn't make a 722 in a 17 caliber and it is an after market barrel. Bolt face is the same as a 222/223/17 Rem.

 

[bheadboy]

I shot and spent time with Mike Walker, designer of the 722/700 222,222m,221 etc.

the early versions were looser in tollerance then later as it became evident the pressures of best loads for 222 etc were higher than the primers (6 1/2 etc) were able to handle, so the 7 1/2 was born, the result was the fireing pin hole needed to be tighter to work well with the higher pressure,

you may find a bushed hole of your 722 solves the problem.

Bob

 

[BoydAllen]

Since I believe that it is the primer that stops the pin, I doubt that excess protrusion is the problem. Sometimes, when a primer is blanked, or pierced, the gasses will cut the tip of the pin leaving it more prone to causing primer failure. Take a close look at the firing pin tip.

 

[jwv2001]

There are many causes of your problem. Bushing the firing pin can certainly be a possible cure. An easy thing to try, is just using a thicker primer cup. Try a CCI BR4, or any small rifle magnum primer and see if you are still getting the metal flow into the primer hole.
I have heard by more than one that Gre-Tan is the way to go if you want the firing pin hole bushed. Here is a link to the specific page on his website with the price.
http://www.gretanrifles.com/bushfiringpin.asp